Pipe wrench



Dec. 9

R. W. M MULLEN PIPE WRENCH Filed March 1924 gwuentoz v abko zmug 5 Patented Dec. 2, 1924.

ROBERT W. MGMULLEN, 0F BRISTOW, OKLAHOMA.

PIPE WRENCH.

Application fifled March 11, 1924. Serial No. 698,519.

To all whom it may concern:

Be it known that I, ROBERT l/V. MOMULLEN, a citizen of the United States, residing at Bristow, in the county of Greek and State of Oklahoma, have invented certain new and useful Improvements in Pipe Wrenches, of which the following is a specification.

My invention relates to wrenches which are primarily intended for unscrewing nipples or broken pipes from pipe connections.

Another object of the invention is to provide a very simple tool which cannot readily get out of order, being made of substantial parts. The wrench is adapted to automatically grip the nipple or broken pipe when turned in one direction and release the same when turned in the opposite direction.

In the accompanying drawing, one embodiment of the invention is illustrated, and-- Figure 1 is a perspective view of a pipe union with the tool inserted;

Figure 2 is a side elevation of the wrench, and

Figure 3 is a horizontal section along line 33 of Figure 2.

In the drawing, reference numeral 10 represents a pipe union from which a nipple or broken pipe 11 is to be removed.

The wrench consists of a stem 12 having a square or flat tip 13 at one end and an enlarged head 14 at the other end. This head is preferably made separate and firmly secured or keyed on the stem 1:2, as best seen in Figure 3, and has a slight downward taper.

The cross section of the head 14 is of irregular shape but its two opposite ends 15 are circular and swung from the center of the head on a radius slightly less than the inside radius of the nipple to be removed.

On the head 14 are hinged a pair of segmental jaws 16 each connected with the head by means of a pivot pin 17. The outer cir' cular face of each jaw is provided with ratchet teeth 18 all pointing in one direction and so arranged that if the pipe or nipple to be removed has a right hand thread the teeth will grip when the wrench is turned in left hand direction. The jaws have a limited swinging motion around their pivot pins 17 and are normally spread apart by means of compression springs 19 engaging corresponding surfaces of the jaws and the head 14:.

In order to obtain a strong connection between the jaws and the head, each jaw is provided with a tongue 20 engaging between projecting ledges 21 through which the pivot pin 17 is driven (see Figures 2 and 3).

When in operation the head of the wrench is inserted in the nipple 11 after the segmental jaws 16 have first been compressed sufficiently to permit the insertion of the wrench in the nipple. WVith a socket wrench or any other suitable tool engaging the tip 13 of the shank 12, the latter is now turned to permit the gripping of the ratchet teeth 18 in the interior surface of the nipple. The wrench need only be turned a few degrees in one direction and them reversed to obtain another hold on the nipple and this is repeated until the work is completed.

The exterior surface of each segment 16 is given the same taper as that of the head 14:.

Having thus described the invention, what is claimed as new is:

A wrench for the purpose set forth comprising a downwardly tapered head having arcuate ends and chordal sides and provided with diametrically opposite recesses intermediate its lateral faces, an operating stem rigidly connected to the head, downwardly tapered segmental jaws having arcuate serrated outer sides, a tongue at one end of each jaw extending into one of the recesses in the head, a pivot pin engaging in said tongue and in the head above and below the tongue to retain the tongue in the recess, and compression springs inserted between the head and the opposed inner sides of the jaws and tending to swing the jaws outwardly, the outward movement of the jaws being limited by contact of the sides of the jaws with the rhordal sides of the heads.

In testimony whereof I affiX my signature,

ROBERT W. MCMULLEN. [11.8.] 

